Symbolic link following in F5 BIG-IP configuration and tmsh utilities (libarchive)

1) UNIX symbolic link following

EUVDB-ID: #VU61393

Risk: Low

CVSSv3.1: 6.7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:U/RC:C]

CVE-ID: CVE-2021-23177

CWE-ID: CWE-61 - UNIX Symbolic Link (Symlink) Following

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a symlink following issue when extracting files from archive, which can lean to changing ACLs of the target of the link. A local user can create a specially crafted archive, trick the victim into extracting files from it and escalate privileges on the system.

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

BIG-IP: 15.0.0 - 17.1.1.3

CPE2.3

• cpe:2.3:h:f5_networks:big-ip:16.1.5:*:*:*:*:*:*:
• cpe:2.3:h:f5_networks:big-ip:15.1.10.4:*:*:*:*:*:*:
• cpe:2.3:h:f5_networks:big-ip:17.1.1.3:*:*:*:*:*:*:
• cpe:2.3:h:f5_networks:big-ip:17.0.0.2:*:*:*:*:*:*:
• cpe:2.3:h:f5_networks:big-ip:16.0.1.2:*:*:*:*:*:*:
• cpe:2.3:h:f5_networks:big-ip:15.0.1.4:*:*:*:*:*:*:

External links

http://my.f5.com/manage/s/article/K000140961

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.